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1.
Thromb J ; 21(1): 41, 2023 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-37069620

RESUMEN

BACKGROUND: Blood transfusion and previous stroke history are two independent risk factors of venous thromboembolism (VTE) in stroke patients. Whether the potential interaction of transfusion history and previous stroke history is associated with a greater risk of VTE remains unclear. This study aims to explore whether the combination of transfusion history and previous stroke history increases the risk of VTE among Chinese stroke patients. METHODS: A total of 1525 participants from the prospective Stroke Cohort of Henan Province were enrolled in our study. Multivariate logistic regression models were used to explore the associations among transfusion history, previous stroke history and VTE. The interaction was evaluated on both multiplicative and additive scales. The odds ratio (95% CI), relative excess risk of interaction (RERI), attributable proportion (AP), and synergy index (S) of interaction terms were used to examine multiplicative and additive interactions. Finally, we divided our population into two subgroups by National Institutes of Health Stroke Scale (NIHSS) score and re-evaluated the interaction effect in both scales. RESULTS: A total of 281 (18.4%) participants of 1525 complicated with VTE. Transfusion and previous stroke history were associated with an increased risk of VTE in our cohort. In the multiplicative scale, the combination of transfusion and previous stroke history was statistically significant on VTE in both unadjusted and adjusted models (P<0.05). For the additive scale, the RERI shrank to 7.016 (95% CI: 1.489 ~ 18.165), with the AP of 0.650 (95% CI: 0.204 ~ 0.797) and the S of 3.529 (95% CI: 1.415 ~ 8.579) after adjusting for covariates, indicating a supra-additive effect. In subgroups, the interaction effect between transfusion history and previous stroke history was pronouncedly associated with the increased risk of VTE in patients with NIHSS score > 5 points (P<0.05). CONCLUSIONS: Our results suggest that there may be a potential synergistic interaction between transfusion history and previous stroke history on the risk of VTE. Besides, the percentage of VTE incidence explained by interaction increased with the severity of stroke. Our findings will provide valuable evidence for thromboprophylaxis in Chinese stroke patients.

2.
Prep Biochem Biotechnol ; 51(10): 1056-1059, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33775215

RESUMEN

It is a challenge for many researchers to separate volatile compounds. In this study, we introduce a rapid and efficient method of separating target compound from the twigs of Cinnamomum cassia by high performance counter-current chromatography. Under the bioassay guidance, the total extract exhibited a potential activity against NO production in RAW 264.7 macrophages and the total extract was further separated by high performance counter-current chromatography. Cinnamaldehyde (1) was enriched by counter-current chromatography (CCC) with reversed-phase mode using n-hexane-ethyl acetate-methanol-water (1:1:1:1,v/v/v/v) as the solvent system. Further identification was achieved by high performance liquid chromatography (HPLC).


Asunto(s)
Acroleína/análogos & derivados , Cinnamomum aromaticum/química , Distribución en Contracorriente , Acroleína/aislamiento & purificación , Acroleína/metabolismo , Cromatografía Líquida de Alta Presión , Cinnamomum aromaticum/metabolismo , Hexanos/química , Metanol/química , Solventes/química , Agua/química
3.
Proc Natl Acad Sci U S A ; 113(40): E5944-E5951, 2016 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-27647907

RESUMEN

Influenza virus strain-specific monoclonal antibodies (mAbs) provide protection independent of Fc gamma receptor (FcγR) engagement. In contrast, optimal in vivo protection achieved by broadly reactive mAbs requires Fc-FcγR engagement. Most strain-specific mAbs target the head domain of the viral hemagglutinin (HA), whereas broadly reactive mAbs typically recognize epitopes within the HA stalk. This observation has led to questions regarding the mechanism regulating the activation of Fc-dependent effector functions by broadly reactive antibodies. To dissect the molecular mechanism responsible for this dichotomy, we inserted the FLAG epitope into discrete locations on HAs. By characterizing the interactions of several FLAG-tagged HAs with a FLAG-specific antibody, we show that in addition to Fc-FcγR engagement mediated by the FLAG-specific antibody, a second intermolecular bridge between the receptor-binding region of the HA and sialic acid on effector cells is required for optimal activation. Inhibition of this second molecular bridge, through the use of an F(ab')2 or the mutation of the sialic acid-binding site, renders the Fc-FcγR interaction unable to optimally activate effector cells. Our findings indicate that broadly reactive mAbs require two molecular contacts to possibly stabilize the immunologic synapse and potently induce antibody-dependent cell-mediated antiviral responses: (i) the interaction between the Fc of a mAb bound to HA with the FcγR of the effector cell and (ii) the interaction between the HA and its sialic acid receptor on the effector cell. This concept might be broadly applicable for protective antibody responses to viral pathogens that have suitable receptors on effector cells.


Asunto(s)
Anticuerpos Antivirales/inmunología , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Orthomyxoviridae/inmunología , Receptores Fc/metabolismo , Secuencia de Aminoácidos , Anticuerpos Monoclonales/metabolismo , Anticuerpos Antivirales/química , Citotoxicidad Celular Dependiente de Anticuerpos , Epítopos/química , Células HEK293 , Glicoproteínas Hemaglutininas del Virus de la Influenza/química , Humanos , Inmunidad Celular , Modelos Biológicos , Modelos Moleculares , Ácido N-Acetilneuramínico/metabolismo , Receptores Fc/química
4.
Proc Natl Acad Sci U S A ; 113(42): 11931-11936, 2016 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-27698132

RESUMEN

The generation of strain-specific neutralizing antibodies against influenza A virus is known to confer potent protection against homologous infections. The majority of these antibodies bind to the hemagglutinin (HA) head domain and function by blocking the receptor binding site, preventing infection of host cells. Recently, elicitation of broadly neutralizing antibodies which target the conserved HA stalk domain has become a promising "universal" influenza virus vaccine strategy. The ability of these antibodies to elicit Fc-dependent effector functions has emerged as an important mechanism through which protection is achieved in vivo. However, the way in which Fc-dependent effector functions are regulated by polyclonal influenza virus-binding antibody mixtures in vivo has never been defined. Here, we demonstrate that interactions among viral glycoprotein-binding antibodies of varying specificities regulate the magnitude of antibody-dependent cell-mediated cytotoxicity induction. We show that the mechanism responsible for this phenotype relies upon competition for binding to HA on the surface of infected cells and virus particles. Nonneutralizing antibodies were poor inducers and did not inhibit antibody-dependent cell-mediated cytotoxicity. Interestingly, anti-neuraminidase antibodies weakly induced antibody-dependent cell-mediated cytotoxicity and enhanced induction in the presence of HA stalk-binding antibodies in an additive manner. Our data demonstrate that antibody specificity plays an important role in the regulation of ADCC, and that cross-talk among antibodies of varying specificities determines the magnitude of Fc receptor-mediated effector functions.


Asunto(s)
Anticuerpos Antivirales/inmunología , Citotoxicidad Celular Dependiente de Anticuerpos , Epítopos/inmunología , Virus de la Influenza A/inmunología , Gripe Humana/inmunología , Anticuerpos Neutralizantes/inmunología , Afinidad de Anticuerpos/inmunología , Antígenos Virales/química , Antígenos Virales/inmunología , Antígenos Virales/metabolismo , Unión Competitiva , Biomarcadores , Línea Celular , Epítopos/metabolismo , Glicoproteínas Hemaglutininas del Virus de la Influenza/química , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Humanos , Fragmentos Fc de Inmunoglobulinas/inmunología , Fragmentos Fc de Inmunoglobulinas/metabolismo , Inmunoglobulina G/inmunología , Gripe Humana/metabolismo , Gripe Humana/virología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Modelos Biológicos , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Receptores Fc/metabolismo
5.
J Virol ; 91(19)2017 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-28724768

RESUMEN

We previously demonstrated that the combination of synthetic small-molecule Toll-like receptor 4 (TLR4) and TLR7 ligands is a potent adjuvant for recombinant influenza virus hemagglutinin, inducing rapid and sustained immunity that is protective against influenza viruses in homologous, heterologous, and heterosubtypic murine challenge models. Combining the TLR4 and TLR7 ligands balances Th1 and Th2-type immune responses for long-lived cellular and neutralizing humoral immunity against the viral hemagglutinin. Here, we demonstrate that the protective response induced in mice by this combined adjuvant is dependent upon TLR4 and TLR7 signaling via myeloid differentiation primary response gene 88 (MyD88), indicating that the adjuvants function in vivo via their known receptors, with negligible off-target effects, to induce protective immunity. The combined adjuvant acts via MyD88 in both bone marrow-derived and non-bone marrow-derived radioresistant cells to induce hemagglutinin-specific antibodies and protect mice against influenza virus challenge. The protective efficacy generated by immunization with this adjuvant and recombinant hemagglutinin antigen is transferable with serum from immunized mice to recipient mice in a homologous, but not a heterologous, H1N1 viral challenge model. Depletion of CD4+ cells after an established humoral response in immunized mice does not impair protection from a homologous challenge; however, it does significantly impair recovery from a heterologous challenge virus, highlighting an important role for vaccine-induced CD4+ cells in cross-protective vaccine efficacy. The combination of the two TLR agonists allows for significant dose reductions of each component to achieve a level of protection equivalent to that afforded by either single agent at its full dose.IMPORTANCE Development of novel adjuvants is needed to enhance immunogenicity to provide better protection from seasonal influenza virus infection and improve pandemic preparedness. We show here that several dose combinations of synthetic TLR4 and TLR7 ligands are potent adjuvants for recombinant influenza virus hemagglutinin antigen induction of humoral and cellular immunity against viral challenges. The components of the combined adjuvant work additively to enable both antigen and adjuvant dose sparing while retaining efficacy. Understanding an adjuvant's mechanism of action is a critical component for preclinical safety evaluation, and we demonstrate here that a combined TLR4 and TLR7 adjuvant signals via the appropriate receptors and the MyD88 adaptor protein. This novel adjuvant combination contributes to a more broadly protective vaccine while demonstrating an attractive safety profile.


Asunto(s)
Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Glicoproteínas de Membrana/inmunología , Factor 88 de Diferenciación Mieloide/inmunología , Infecciones por Orthomyxoviridae/inmunología , Receptor Toll-Like 4/inmunología , Receptor Toll-Like 7/inmunología , Proteínas Adaptadoras del Transporte Vesicular/genética , Adyuvantes Inmunológicos/farmacología , Animales , Anticuerpos Antivirales/inmunología , Antígenos Virales/inmunología , Femenino , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Vacunas contra la Influenza/inmunología , Pulmón/inmunología , Pulmón/virología , Glicoproteínas de Membrana/genética , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/genética , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/virología , Células TH1/inmunología , Células Th2/inmunología , Receptor Toll-Like 4/genética , Receptor Toll-Like 7/genética , Vacunación
6.
J Infect Dis ; 214(2): 248-57, 2016 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-27034343

RESUMEN

High-affinity-antibody production, T-cell activation, and interferon upregulation all contribute to protective immunity that occurs in humans following influenza immunization. Hematopoietic cell-specific PTPN22 encodes lymphoid phosphatase (Lyp), which regulates lymphocyte antigen receptor and pattern recognition receptor (PRR) signaling. A PTPN22 variant, R620W (LypW), predisposes to autoimmune and infectious diseases and confers altered signaling through antigen receptors and PRRs. We tested the hypothesis that LypW-bearing humans would have diminished immune response to trivalent influenza vaccine (TIV). LypW carriers exhibited decreased induction of influenza virus-specific CD4(+) T cells expressing effector cytokines and failed to increase antibody affinity following TIV receipt. No differences between LypW carriers and noncarriers were observed in virus-specific CD8(+) T-cell responses, early interferon transcriptional responses, or myeloid antigen-presenting cell costimulatory molecule upregulation. The association of LypW with defects in TIV-induced CD4(+) T-cell expansion and antibody affinity maturation suggests that LypW may predispose individuals to have a diminished capacity to generate protective immunity against influenza virus.


Asunto(s)
Inmunidad Adaptativa , Anticuerpos Antivirales/sangre , Inmunidad Innata , Vacunas contra la Influenza/inmunología , Orthomyxoviridae/inmunología , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética , Adolescente , Adulto , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas Mutantes/genética , Adulto Joven
7.
J Virol ; 89(7): 3610-8, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25589655

RESUMEN

UNLABELLED: Current influenza virus vaccines rely upon the accurate prediction of circulating virus strains months in advance of the actual influenza season in order to allow time for vaccine manufacture. Unfortunately, mismatches occur frequently, and even when perfect matches are achieved, suboptimal vaccine efficacy leaves several high-risk populations vulnerable to infection. However, the recent discovery of broadly neutralizing antibodies that target the hemagglutinin (HA) stalk domain has renewed hope that the development of "universal" influenza virus vaccines may be within reach. Here, we examine the functions of influenza A virus hemagglutinin stalk-binding antibodies in an endogenous setting, i.e., as polyclonal preparations isolated from human sera. Relative to monoclonal antibodies that bind to the HA head domain, the neutralization potency of monoclonal stalk-binding antibodies was vastly inferior in vitro but was enhanced by several orders of magnitude in the polyclonal context. Furthermore, we demonstrated a surprising enhancement in IgA-mediated HA stalk neutralization relative to that achieved by antibodies of IgG isotypes. Mechanistically, this could be explained in two ways. Identical variable regions consistently neutralized virus more potently when in an IgA backbone compared to an IgG backbone. In addition, HA-specific memory B cells isolated from human peripheral blood were more likely to be stalk specific when secreting antibodies of IgA isotypes compared to those secreting IgG. Taken together, our data provide strong evidence that HA stalk-binding antibodies perform optimally when in a polyclonal context and that the targeted elicitation of HA stalk-specific IgA should be an important consideration during "universal" influenza virus vaccine design. IMPORTANCE: Influenza viruses remain one of the most worrisome global public health threats due to their capacity to cause pandemics. While seasonal vaccines fail to protect against the emergence of pandemic strains, a new class of broadly neutralizing antibodies has been recently discovered and may be the key to developing a "universal" influenza virus vaccine. While much has been learned about the biology of these antibodies, most studies have focused only on monoclonal antibodies of IgG subtypes. However, the study of monoclonal antibodies often fails to capture the complexity of antibody functions that occur during natural polyclonal responses. Here, we provide the first detailed analyses of the biological activity of these antibodies in polyclonal contexts, comparing both IgG and IgA isotypes isolated from human donors. The striking differences observed in the functional properties of broadly neutralizing antibodies in polyclonal contexts will be essential for guiding design of "universal" influenza virus vaccines and therapeutics.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Inmunoglobulina A/inmunología , Virus de la Influenza A/inmunología , Adulto , Femenino , Humanos , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Gripe Humana/prevención & control , Masculino , Persona de Mediana Edad , Adulto Joven
8.
Methods ; 90: 95-100, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-25957674

RESUMEN

The discovery of broadly-neutralizing antibodies that bind to the hemagglutinin stalk/stem domain has opened exciting new avenues for the development of "universal" influenza virus vaccines and therapeutics. Unlike strain-specific antibodies which bind to the hemagglutinin head domain and inhibit receptor binding, antibodies that bind to the stalk domain function to inhibit later stages of infection. The hemagglutination inhibition assay has long been the standard for evaluating titers of neutralizing hemagglutinin-specific antibodies in serum. The assay has the beneficial properties of being relatively rapid, easy-to-perform, and requires very little specialized equipment. Historically, hemagglutination inhibition titers of 40 or above against a given strain of influenza has been considered a correlate of protection on a population level. Unfortunately, this assay cannot be used to measure titers of hemagglutinin stalk-specific antibodies due to their lack of hemagglutination inhibiting activity. This has necessitated the development of novel reagents and assays capable of sensitive and specific detection of broadly-neutralizing HA stalk-binding antibodies in polyclonal mixtures. Here, we describe a novel microneutralization-based assay that utilizes recombinant influenza A viruses expressing chimeric hemagglutinin molecules and 'exotic' neuraminidase to measure titers of broadly-neutralizing antibodies in polyclonal preparations.


Asunto(s)
Anticuerpos Neutralizantes , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Virus de la Influenza A/inmunología , Pruebas de Neutralización/métodos , Animales , Perros , Ensayo de Inmunoadsorción Enzimática , Humanos , Células de Riñón Canino Madin Darby
9.
Gastroenterology ; 145(5): 966-969.e7, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23891978

RESUMEN

The narrow species tropism of hepatitis C virus (HCV) limits animal studies. We found that pigtail macaque (Macaca nemestrina) hepatic cells derived from induced pluripotent stem cells support the entire HCV life cycle, although infection efficiency was limited by defects in the HCV cell entry process. This block was overcome by either increasing occludin expression, complementing the cells with human CD81, or infecting them with a strain of HCV with less restricted requirements for CD81. Using this system, we can modify viral and host cell genetics to make pigtail macaques a suitable, clinically relevant model for the study of HCV infection.


Asunto(s)
Modelos Animales de Enfermedad , Hepacivirus/patogenicidad , Hepatitis C/virología , Hepatocitos/virología , Células Madre Pluripotentes Inducidas/virología , Macaca nemestrina , Animales , Línea Celular , Células Cultivadas , Hepatitis C/patología , Hepatitis C/fisiopatología , Hepatocitos/patología , Interacciones Huésped-Patógeno/genética , Humanos , Células Madre Pluripotentes Inducidas/patología , Ocludina/fisiología , Tetraspanina 28/deficiencia , Tetraspanina 28/fisiología , Internalización del Virus , Replicación Viral/fisiología
10.
Obes Facts ; 17(1): 24-36, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37820603

RESUMEN

INTRODUCTION: In obesity-related type 2 diabetes mellitus (T2DM), M1 macrophages aggravate chronic inflammation and insulin resistance. ISG15-conjugation enzyme E2L6 (Ube2L6) has been demonstrated as a promoter of obesity and insulin resistance. This study investigated the function and mechanism of Ube2L6 in M1 macrophage polarization in obesity. METHODS: Obesity was induced in Ube2L6AKO mice and age-matched Ube2L6flox/flox control mice by high-fat diet (HFD). Stromal vascular cells were isolated from the epididymal white adipose tissue of mice. Polarization induction was performed in mouse bone marrow-derived macrophages (BMDMs) by exposure to IFN-γ, lipopolysaccharide, or IL-4. F4/80 expression was assessed by immunohistochemistry staining. Expressions of M1/M2 macrophage markers and target molecules were determined by flow cytometry, RT-qPCR, and Western blotting, respectively. Protein interaction was validated by co-immunoprecipitation (Co-IP) assay. The release of TNF-α and IL-10 was detected by ELISA. RESULTS: The polarization of pro-inflammatory M1 macrophages together with an increase in macrophage infiltration was observed in HFD-fed mice, which could be restrained by Ube2L6 knockdown. Additionally, Ube2L6 deficiency triggered the repolarization of BMDMs from M1 to M2 phenotypes. Mechanistically, Ube2L6 promoted the expression and activation of signal transducer and activator of transcription 1 (STAT1) through interferon-stimulated gene 15 (ISG15)-mediated ISGlylation, resulting in M1 macrophage polarization. CONCLUSION: Ube2L6 exerts as an activator of STAT1 via post-translational modification of STAT1 by ISG15, thereby triggering M1 macrophage polarization in HFD-fed obese mice. Overall, targeting Ube2L6 may represent an effective therapeutic strategy for ameliorating obesity-related T2DM.


Asunto(s)
Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Animales , Ratones , Tejido Adiposo/metabolismo , Diabetes Mellitus Tipo 2/etiología , Diabetes Mellitus Tipo 2/metabolismo , Dieta Alta en Grasa/efectos adversos , Inflamación/etiología , Inflamación/metabolismo , Macrófagos , Ratones Endogámicos C57BL , Ratones Obesos , Obesidad/etiología , Obesidad/metabolismo
11.
Nat Commun ; 15(1): 3485, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664427

RESUMEN

Spider silk exhibits an excellent combination of high strength and toughness, which originates from the hierarchical self-assembled structure of spidroin during fiber spinning. In this work, superfine nanofibrils are established in polyelectrolyte artificial spider silk by optimizing the flexibility of polymer chains, which exhibits combination of breaking strength and toughness ranging from 1.83 GPa and 238 MJ m-3 to 0.53 GPa and 700 MJ m-3, respectively. This is achieved by introducing ions to control the dissociation of polymer chains and evaporation-induced self-assembly under external stress. In addition, the artificial spider silk possesses thermally-driven supercontraction ability. This work provides inspiration for the design of high-performance fiber materials.


Asunto(s)
Nanofibras , Polielectrolitos , Seda , Arañas , Animales , Nanofibras/química , Arañas/química , Seda/química , Polielectrolitos/química , Resistencia a la Tracción , Músculos , Materiales Biomiméticos/química
12.
Curr Pharm Des ; 29(12): 940-946, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37005539

RESUMEN

BACKGROUND: Colorectal cancer (CRC) is the most common type of gastrointestinal tumor, but the available pharmacological treatment is insufficient. As a traditional Chinese medicine, the green walnut husks (QLY) exhibit anti-inflammatory, analgesic, anti-bacterial and anti-tumor effects. However, the effects and molecular mechanisms of QLY extracts on CRC were not yet made known. OBJECTIVE: This study aims to provide efficient and low toxicity drugs for the treatment of CRC. The purpose of this study is to explore the anti-CRC effect and mechanism of QLY, providing preliminary data support for clinical research of QLY. METHODS: Western blotting, Flow cytometry, immunofluorescence, Transwell, MTT, Cell proliferation assay, and xenograft model were used to perform the research. RESULTS: In this study, the potential of QLY to inhibit the proliferation, migration invasion and induce apoptosis of the mouse colorectal cancer cell line CT26 in vitro was identified. The xenograft tumor model of CRC noted that QLY suppressed tumor growth without sacrificing body weight in mice. In addition, QLY-induced apoptosis in tumor cells through NLRC3/PI3K/AKT signaling pathway was revealed. CONCLUSION: QLY regulates the levels of mTOR, Bcl-2 and Bax by affecting the NLRC3/PI3K/AKT pathway to promote apoptosis of tumor cells, suppressing cell proliferation, invasion and migration, and subsequently preventing the progression of colon cancer.


Asunto(s)
Neoplasias Colorrectales , Juglans , Humanos , Animales , Ratones , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Neoplasias Colorrectales/metabolismo , Apoptosis , Proliferación Celular , Línea Celular Tumoral , Movimiento Celular , Péptidos y Proteínas de Señalización Intercelular/uso terapéutico
13.
Natl Sci Rev ; 10(1): nwac196, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36684513

RESUMEN

Human muscles can grow and change their length with body development; therefore, artificial muscles that modulate their morphology according to changing needs are needed. In this paper, we report a strategy to transform an artificial muscle into a new muscle with a different morphology by thermodynamic-twist coupling, and illustrate its structural evolution during actuation. The muscle length can be continuously modulated over a large temperature range, and actuation occurs by continuously changing the temperature. This strategy is applicable to different actuation modes, including tensile elongation, tensile contraction and torsional rotation. This is realized by twist insertion into a fibre to produce torsional stress. Fibre annealing causes partial thermodynamic relaxation of the spiral molecular chains, which serves as internal tethering and inhibits fibre twist release, thus producing a self-supporting artificial muscle that actuates under heating. At a sufficiently high temperature, further relaxation of the spiral molecular chains occurs, resulting in a new muscle with a different length. A structural study provides an understanding of the thermodynamic-twist coupling. This work provides a new design strategy for intelligent materials.

14.
J Affect Disord ; 333: 535-542, 2023 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-37086797

RESUMEN

BACKGROUND: Mental health is an essential dimension of healthy aging. The number and severity of disabled elderly in China show an increasing tendency year by year. Due to their impaired ability of daily activities, reduced social participation and reduced self-care ability, they are more prone to depression and anxiety. METHOD: We included 2131 individuals aged 65 and older from the Chinese Longitudinal Healthy Longevity Survey (CLHLS 2017-2018). We used the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) and the Generalized Anxiety Disorder scale-7 (GAD-7) to assess depression and anxiety, respectively. The structure of depressive and anxiety symptoms was characterized using "Expected Influence" and "Bridge Expected Influence" as centrality indices in the symptom network. Network stability was tested using a case-dropping bootstrap procedure. Finally, a Network Comparison Test (NCT) was conducted to examine whether network characteristics differed by gender. RESULTS: Network analysis revealed that nodes CESD3 (Felt sadness), GAD2 (Uncontrollable worry), and GAD4 (Trouble relaxing) were the primary symptoms of the anxiety-depression network. Anxiety and depression were united by the symptoms of CESD9 (Could not get going), GAD1 (Nervousness or anxiety), CESD10 (Sleep quality), and GAD4 (Trouble relaxing). Additionally, Gender did not significantly affect the network structure. CONCLUSION: Central symptoms (e.g., felt sadness, uncontrollable worry and trouble relaxing) and key bridge symptoms (e.g., could not get going, nervousness and anxiety) in the depressive and anxiety symptoms network may be used as potential targets for intervention among disabled elderly who is at risk for or suffer from depressive and anxiety symptoms.


Asunto(s)
Ansiedad , Depresión , Pueblos del Este de Asia , Anciano , Humanos , Ansiedad/diagnóstico , Ansiedad/epidemiología , Ansiedad/psicología , Depresión/diagnóstico , Depresión/epidemiología , Depresión/psicología , Longevidad , Personas con Discapacidad
15.
Adv Mater ; 34(27): e2201843, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35509216

RESUMEN

Spider dragline silk is draw-spun from soluble, ß-sheet-crosslinked spidroin in aqueous solution. This spider silk has an excellent combination of strength and toughness, which originates from the hierarchical structure containing ß-sheet crosslinking points, spiral nanoassemblies, a rigid sheath, and a soft core. Inspired by the spidroin structure and spider spinning process, a soluble and crosslinked nanogel is prepared and crosslinked fibers are drew spun with spider-silk-like hierarchical structures containing cross-links, aligned nanoassemblies, and sheath-core structures. Introducing nucleation seeds in the nanogel solution, and applying prestretch and a spiral architecture in the nanogel fiber, further tunes the alignment and assembly of the polymer chains, and enhances the breaking strength (1.27 GPa) and toughness (383 MJ m-3 ) to approach those of the best dragline silk. Theoretical modeling provides understanding for the dependence of the fiber's spinning capacity on the nanogel size. This work provides a new strategy for the direct spinning of tough fiber materials.


Asunto(s)
Fibroínas , Arañas , Animales , Fibroínas/química , Nanogeles , Seda/química , Agua
16.
Nat Prod Res ; 36(2): 668-673, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32691629

RESUMEN

One novel pentacyclic triterpene, 24-dimethoxymethyl-3ß,6ß,19α- trihydroxy -12-en-28-oic acid (1), along with six known compounds 2-7, were isolated from the canes of Uncaria sessilifructus Roxb. Their structures were determined according to spectroscopic and spectrometric analysis. The anti-inflammatory activities of the isolated compounds (1-7) were scanned against NO production in LPS-activated RAW 264.7 macrophages by MTS assay, however no activities were observed.


Asunto(s)
Rubiaceae , Triterpenos , Uncaria , Estructura Molecular , Triterpenos Pentacíclicos/farmacología , Extractos Vegetales , Triterpenos/farmacología
17.
Se Pu ; 38(12): 1363-1368, 2020 Dec 08.
Artículo en Zh | MEDLINE | ID: mdl-34213250

RESUMEN

Brazilein is among the main chemical constituents of Caesalpinia sappan. It has diverse pharmacological activities. Modern pharmacological studies have shown that the compound has antitumor, anti-inflammatory, antibacterial, antioxidant, immunomodulatory, and other pharmacological activities. Brazilein is often used as a stain in various industries. The separation of brazilein by traditional column chromatography will not only result in contamination of the chromatographic column materials, but also lead to loss of the active ingredient. Countercurrent chromatography is an advanced liquid-liquid chromatographic separation technique. It has been widely used for natural product separation and isolation as it offers several advantages, such as low solvent consumption, a highly selective solvent system, and high recoveries. Typical countercurrent chromatography techniques include centrifugal partition chromatography (CPC), high-speed countercurrent chromatography (HSCCC), and high performance countercurrent chromatography (HPCCC). It is well known that choosing a suitable solvent system is vital in countercurrent separation. Therefore, two methods were introduced for choosing a suitable solvent system. One is the generally useful estimation of solvent systems (GUESS) method, which employs thin-layer chromatography (TLC) to identify a suitable solvent system with minimal labor for the rapid purification of target compounds, and another is the Shake-Flash method. The solvent system could be determined by observing the distribution of the sample in the upper and lower phases. Two kinds of solvent systems were screened using the TLC-GUESS and Shake-Flash methods, and tested through the analysis mode of the HPCCC instrument. The results showed that chloroform-methanol-water (4:3:2, v/v/v) was the optimal solvent system for HPCCC separation. A total of 15.2 mg of brazilein and 5.7 mg of caesappanin C were obtained from an ethyl acetate extract with high purities (95.6% and 89.0%, analyzed by HPLC) in one step using the preparation mode of HPCCC, the reversed-phase liquid chromatography mode with the apparatus rotated at 1600 r/min, a flow rate of 10 mL/min, separation temperature of 25℃, and detection wavelength of 285 nm. Their structures were determined by spectroscopic and spectrometric analyses. Brazilein stained the solid packing material in the column and was difficult to elute. The results showed that the use of HPCCC for the separation of brazilein can not only prevent the loss of target active ingredients in Caesalpinia sappan, but also shorten the separation and purification times and improve the operating efficiency. Therefore, HPCCC can be used for the separation and preparation of other pigment compounds in Caesalpinia sappan and other dye plants.


Asunto(s)
Benzopiranos , Caesalpinia , Indenos , Extractos Vegetales/química , Benzopiranos/aislamiento & purificación , Caesalpinia/química , Cromatografía Líquida de Alta Presión , Distribución en Contracorriente , Indenos/aislamiento & purificación
18.
Cell Rep ; 32(1): 107873, 2020 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-32640238

RESUMEN

The tumor microenvironment is rich with immune-suppressive macrophages that are associated with cancer progression and resistance to immune checkpoint therapy. Using pre-treatment tumor biopsies complemented with single-cell RNA sequencing (RNA-seq), we characterize intratumoral immune heterogeneity to unveil potential mechanisms of resistance to avelumab (anti-PD-L1). We identify a proinflammatory F480+MHCII+Ly6Clo macrophage population that is associated with response rather than resistance to avelumab. These macrophages are the primary source of the interferon-inducible chemokine Cxcl9, which facilitates the recruitment of protective Cxcr3+ T cells. Consequently, the efficacy of avelumab in mouse tumor models is dependent on Cxcr3 and Cxcl9, and baseline levels of Cxcl9 in patients treated with avelumab are associated with clinical response and overall survival. These data suggest that, within the broadly immune-suppressive macrophage compartment, a pro-inflammatory population exists that promotes responsiveness to PD-L1 blockade.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacología , Quimiocina CXCL9/metabolismo , Inflamación/patología , Macrófagos Asociados a Tumores/patología , Animales , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Femenino , Inhibidores de Puntos de Control Inmunológico/farmacología , Ratones Endogámicos BALB C , Modelos Biológicos , Monocitos/efectos de los fármacos , Monocitos/metabolismo , Resultado del Tratamiento , Macrófagos Asociados a Tumores/efectos de los fármacos
19.
J Immunother Cancer ; 8(1)2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32474414

RESUMEN

BACKGROUND: CD40 is a compelling target for cancer immunotherapy, however, attempts to successfully target this pathway have consistently been hampered by dose-limiting toxicity issues in the clinic that prevents the administration of efficacious doses. METHODS: Here, using cytokine and cytokine receptor depletion strategies in conjunction with a potent CD40 agonist, we investigated mechanisms underlying the two primary sources of CD40 agonist-associated toxicity, hepatotoxicity and cytokine release syndrome (CRS). RESULTS: We demonstrate that CD40 agonist -induced hepatotoxicity and CRS are mechanistically independent. Historical data have supported a role for interleukin-6 (IL-6) in CRS-associated wasting, however, our findings instead show that an inflammatory cytokine network involving TNF, IL-12p40, and IFNγ underlie this process. Deficiency of TNF or IFNγ did not influence CD40-induced hepatitis however loss of IL-12p40 significantly decreased circulating concentrations of liver enzymes and reduced the frequency of activated CD14+MHCII+ myeloid cells in the liver, indicating a role for IL-12p40 in liver pathology. CONCLUSIONS: As clinical research programs aim to circumnavigate toxicity concerns while maintaining antitumor efficacy it will be essential to understand which features of CD40 biology mediate antitumor function to develop both safe and efficacious agonists.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico , Inmunoterapia/métodos , Subunidad p40 de la Interleucina-12/efectos adversos , Animales , Femenino , Humanos , Ratones
20.
Curr Pharm Des ; 25(46): 4919-4927, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31830892

RESUMEN

BACKGROUND: Anthocyanins are a type of flavonoids that are natural water soluble glycosidic pigments with efficacious anti-cancer effects, which have good biological activity against many cancers including colorectal cancer (CRC). However, the exact molecular mechanism used by anthocyanins against cancer is unclear; it is also unclear what a reasonable dosage might be for their use against colorectal cancer. METHODS: Western blotting, immunohistochemistry, MTT assay, xenograft model, and hematoxylin-eosin (HE) staining were used to perform the experiments. RESULTS: Compared with the control group, anthocyanins could significantly inhibit the cell viability and proliferation and promote the apoptosis of human colon cancer HT29 cells. Furthermore, anthocyanins reduced tumor weight and volume in a colon tumor mouse model and downregulated the expression of PI3K protein, inhibited AKT expression and phosphorylation, decreased the Bcl-2 and Bax ratio and reduced survivin protein expression in the tumor tissue. CONCLUSION: Anthocyanins promoted apoptosis of CRC cells and inhibited colon cancer growth of xenografted tumors. Mechanistically, anthocyanins enhanced the Bcl-2/Bax and caspase-dependent apoptotic pathways through targeting the PI3K/AKT/survivin pathway, resulting in impairment of growth of CRC.


Asunto(s)
Antocianinas/uso terapéutico , Neoplasias del Colon/terapia , Neoplasias Colorrectales/terapia , Animales , Apoptosis , Línea Celular Tumoral , Proliferación Celular , Células HT29 , Humanos , Ratones , Transducción de Señal
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